This invention relates to solid, non-medicinal, sustained release, antimicrobial compositions which comprise a halogenated amide as the active (i.e., antimicrobial) ingredient and a suitable hydrophilic polymer.
Halogenated amides such as 2,2-dibromo-3-nitrilopropionamide are well-known antimicrobials useful in a variety of antimicrobial applications. See, for example, U.S. Pat. Nos. 2,419,888; 3,439,658; 4,241,080; 3,350,164; 3,403,174; 3,647,610; 3,649,166; 3,928,575; Belgian Pat. No. 668,336; and Wolf et al., "2,2-Dibromo-3-Nitrilopropionamide, A Compound with Slimicidal Activity," Applied Microbiology, Vol. 24, No. 4, pp. 581-584 (1972).
Halogenated amides are known to rapidly degrade under use conditions. See, for example, U.S. Pat. No. 3,689,660 and "Rates and Products of Decomposition of 2,2-Dibromo-3-Nitrilopropionamide," Exner et al., J. Agr. Food Chem., Vol. 21, No. 5, pp. 838-842 (1973). This rapid degradation is a beneficial environmental feature; however, the rapid degradation is a severe detriment when biocidal persistence is desired or necessary.
Although it has long been desired in the antimicrobial field to have a composition and/or method to increase the persistence of halogenated amide antimicrobials, heretofore such compositions and/or methods have not been available. The present invention provides for a means of meeting the long felt need in the art by use of compositions containing halogenated amide antimicrobials and hydrophilic polymers.
Polymers suitable for use in the present invention, such as natural and synthetic hydrophilic cellulosic polymers, are known polymers. See, for example, U.S. Pat. Nos. 4,429,120; 4,369,172; and 3,839,319. However, use of such polymers with halogenated amide antimicrobials to obtain solid compositions of increased biocidal persistence has been heretofore unknown. The method of the present invention provides for an unexpected increase in antimicrobial efficiency relative to current state of the art methods of use.